Studies On Vegetative Propagation Of Some Apple Rootstocks:

Nahla Forouk Ahmed Fouda

SUMMARY AND CONCLUSIONThis study was conducted in the experimental station at the Faculty ofAgriculture. Ain-Shams University, during two successive seasons of 1990 -1991and 1991-1992 for studying propagation ability of two apple rootstocks namely,MM.106 and Mc.9 by either stem hardwood cuttings or by air-layering. Producingstandard nursery plants through enhancing rooting ability in both cuttings and airlayersby applying some preplanting / pre-layering treatments were the mainpurpose of this work. Hence, the wounding and dipping/or treated with lanolinepaste in various solutions of ISA combined with date of cuttings preparation ordate of layering application. In addition, anatomical studies were also carried outfor the basal portion of cuttings/or air-layers to throw some lights on the initiationof root primordia and difficulties may be presented and reflected negatively eitheron their initiation or penetration of the adventitious roots through tissues ofcuttings or layers. Thus, the two following field experiments were included:-V. I. Experiments on rooting of MM.106and Mc.9 apple rootstocks bystem hard wood cuttings.V. II. Experiments on Propagation of MM.106 and Mc.9 applerootstocks by air-layering.V. I. Experiments on Rooting of MM.106and Mc.9 apple rootstocks bystem hard wood cuttings.The stem hardwood cuttings of two apple rootstocks, i.e., MM.106 andMC.9 with 15 em. length and 5-7 mm. diameter were prepared from the mediumpart of 1-year old wood collected at three different dates (15th December, 151bJanuary and 15th < February) in both seasons. One factorial experiment was~a8 conducted for every apple cultivar each one including 24 treatments, i.e., icombinations between three collecting dates from one hand and 8 preplantingtreatments applications of dipping the wounded or unwounded cuttings in (water,ISA at 1000, 2000 and 4000 ppm) from the other. All treated cuttings were storedin moist mixture of sand and peat moss (v : v) at equal proportions till tat Marchof each experimental season (planting date) for investigating growth parametersresponses devoted cuttings were planted in wooden boxes contained sand andpeat moss at 1:1 by volum, whereas, the different treatments (combinations) werearranged in a complete randomise design as each treatment was replicated sixtimes and every replicate was represented by 10 cuttings. Meanwhile, othersmaller boxes was devoted from planting treated cuttings needed for anatomicalstudy. Data of some rooting measurements viz. a- Percentage of rooted cuttings,b- Number of roots/cutting and c- Average length of root developed per cuttingwere recorded 7 weeks later for planting date. Since, all planted cuttings in boxeswere carefully taken off and the aforesaid three parameters were immediatelydetermined. Moreover, all succeeded rooted cuttings were counted andtransplanted individually each in a polyethylene bag filled with a mixture ofpeatmoss and sand at equal proportions (v : v). Such rooted cuttings wereallowed to grow for 6 months from transplanting in order to carrying out the othergrowth measurements (Survival %, stem length, root length, number of leaves /rooted cutting, dry weight of leaves, stem, root and total plant dry weight).v. II. Experiments on Propagation of MM.106 and Mc.9 applerootstocksby air-layering:-Two apple rootstocks, i.e., MM.106 and MC.9 were used. The air-layerswith 40-50 Cm. length and 1 - 1.5 Cm. diameter of one-year-old selected shootswere done on two dates (15th August and 15th September) in both seasons.Thus, two factorial experiments were conducted each one including 12treatments, i.e., combinations between two layering dates from one hand and 6pre-layering treatments applications of treated the unwounded or wounded layerswith lanoline paste containing 0, 1000 and 2000 ppm ISA from the other. Layerswere separated after 4 months when the developed roots emerged under thepolyethylene cover of the layers. The same vegetative measurements previouslyestimated with cuttings were recorded during 1990-1991 and 19911992 seasons.As for the anatomical study, air-layering samples (each consisted of oneshoot) were randomly taken weekly during the study to examine their anatomicalstructure may be affect the rooting process.The obtained results in this work could be summarised as follows:-v. I. Experiments of stem hardwood cuttings:-1- No rooting was obtained by Mc.9 apple rootstock cuttings regardless ofcollecting dates and preplanting treatments of wounding and dipping in differentconcentrations of ISA at (0, 1000, 2000 and 4000 ppm.). However, rooting hadbeen taken place in cuttings of MM.106 apple rootstock with a various degreesof success according to the investigated treatments.2- As for response of rooting aspects (7-weeks from planting) of MM.106apple rootstock, to the specific effect of collecting dates, it was quite evident that15th January was more suitable for rooting %. number of roots I cutting andaverage root length during two seasons of study.3- Concerning the specific effect of preplanting treatments on rooting %,number of roots and roots length I cutting data obtained cleared that dipping ofwounded or unwounded cuttings In different concentrations of 18A ( 1000, 2000100and 40000 ppm) were effective than control, while the higher concentration ofISA was more beneficial in this respect.4- As for the interaction effect, obtained results showed that combinationsof dipping both wounded and unwounded cuttings collected on 15th January, inISA at 2000 I 4000 ppm were the superior ones in comparison with others as therooting %, number of roots and root length I cutting during both seasons of studywere concerned. Gnthe other hand, the combination between 15th Januarycollected cuttings and preplanting treatment of dipping in ISA at 4000 ppm withwounding application tended to be of more pronounced effect in this respectduring the two seasons of study.5- Regarding specific effect of collecting dates on survival %, number ofleaves I rooted cutting dry weight of plant organs (Leaves, stem, roots and totalplant) data obtained revealed that the highest values of MM.106 apple rootstockwere closely related to 15th January collected cuttings in this concern.6- Concerning the specific effect of preplanting treatments of woundingand dipping in ISA at 1000, 2000 or 4000 ppm. on survival %, number of leaves Irooted cutting stem length and the dry weight of plant organs (leaves, stem, rootsand total plant) data obtained during both seasons of study showed that dipping ofwounded cuttings in both higher concentrations of ISA (2000 I 4000 ppm) werethe superior.7- As for the interaction effect of both investigated factors, data obtaineddeclared obviously that the combination between 15th January collected cuttingsfrom one hand and dipping in ISA at 4000 ppm. with wounding application werethe superior treatments during the two seasons of study.v. ”.Experiments on airlayering:-lOr1- No rooting was obtained by Mc.9 apple rootstock air-layers carried outeither on 15th August or 15th September regardless of the prelaying treatments’of wounding and ISA applications during the two seasons of study. In thisrespect, rooting was obtained only by MM.106 apple rootstock layers with variousdegree of response depending on combinations of both investigated factorsapplied during two seasons of study.2- As for growth measurements (4-months from practising layers) forMM.106 apple rootstock, data obtained could be concluded as follows :_a- Concerning the specific effect of layering date, it was quite evident that15th August was more suitable than 15th September as successful %, number ofroot I plant, root length, stem length number of leaves I plant and dry weight ofplant organs (leaves, stem, roots and total plant) were concerned dUring twoseasons of study.b- With respect to the specific effect of pre-layering treatments, the datarevealed that treating with ISA at 2000 ppm plus wounding was more suitable forpercent success, number and length of roots, stem length, number of leaves Ilayer and dry weight of plant organs (Leaves, stem, roots and total plant) duringtwo seasons of study.3- As for the interaction effect, data obtained declared obviously thatlayering of wounded shoots that treated with ISA at 2000 ppm on August 15thwas the superior combination as successful % and vegetative measurementsvalues during were concemed both seasons.v. III. Anatomical examination:-Rooting ability of hardwood cuttings and air-layering of Mc.9 and MM.106apple rootstocks was investigated. Wounding and or different concentration of IBAincreased rooting of MM.106 apple rootstock only. The present study showed thatMc.9 has no rooting ability (0.00%) compared to MM.106 which showed arelative higher rooting (32.42 - 73.95%). Anatomical studies revealed that thenon rooting of Mc.9 due to a continuous scleroid sheet which restricted thepenetration of root primordiaL Such layer is not clear in MM.106. In addition,adeventious roots originated from the cambium zone and the pith in MM.106.Generally, the highest rooting percentage and best vegetative growthmeasurements were obtained when cuttings from one year old branches werecollected on 15th. January and treated with ISA at 4000 ppm wounding its base.Also, the same trend was found when air-layers were treated with 2000ppm. ISA + wounding on 15th August during both 1990-1991 and 1991-1992seasons.